1911 Slide Auto Forward

[azuredragon]

I'm encountering a pretty consistent issue with my Springfield Armory Mil-Spec 1911 where a firm smack of the magazine (not excessive in force) on a slide lock reload will bump the slide stop down from inertia and drop the slide. I've played around and have determined it's not a magazine issue since it doesn't make contact with the slide stop when I removed the slide to check. I noticed it does this across a variety of magazines. Most importantly, I decided to do a one-time test where I locked the slide back with no magazine inserted and gave the bottom of the grip a good smack: the slide went into battery. I think we can isolate this to the gun and not the mags.

How would y'all diagnose this? to be clear, I *don't* see this as a benefit to me and I'd rather eliminate this from occurring. Any tips would be greatly appreciated!

[spandexlurch]

I'm encountering a pretty consistent issue with my Springfield Armory Mil-Spec 1911 where a firm smack of the magazine (not excessive in force) on a slide lock reload will bump the slide stop down from inertia and drop the slide. I've played around and have determined it's not a magazine issue since it doesn't make contact with the slide stop when I removed the slide to check. I noticed it does this across a variety of magazines. Most importantly, I decided to do a one-time test where I locked the slide back with no magazine inserted and gave the bottom of the grip a good smack: the slide went into battery. I think we can isolate this to the gun and not the mags.

How would y'all diagnose this? to be clear, I *don't* see this as a benefit to me and I'd rather eliminate this from occurring. Any tips would be greatly appreciated!

I own a S&W M&P 9mm that does this exact same thing. I don't know why and have no solution for it.

[Gunsnwater]

Well you have to examine the slide stop dimple and the plunger and spring. Is the dimple shallow or the plunger worn or short? Is the spring weak? Also how much vertical slop does the slide have? Are you lifting the slide out of engagement with the stop? Don't throw parts at it until you figure out the engagement issues. One last thing is the recoil spring, they need changing after awhile.

[Gunsnwater]

Polymer guns flex enough and they have springs pushing the slide lock down if the stronger mag spring isnt pushing it up by the follower. By the way the plastic one all do it with enough force, but your beating parts up by that much force.

[cdi]

Well you have to examine the slide stop dimple and the plunger and spring. Is the dimple shallow or the plunger worn or short? Is the spring weak? Also how much vertical slop does the slide have? Are you lifting the slide out of engagement with the stop? Don't throw parts at it until you figure out the engagement issues. One last thing is the recoil spring, they need changing after awhile.

This is the answer.

If the parts are made correctly, the slide stop does not need a dimple-
S.A. and just about every other manufacturer can not afford to make 1911s to the old ordnance dept. specifications so you have these kinds of issues.

[azuredragon]

I hate to be really out of the loop but could you explain what the slide stop dimple should be like? This Springfield has just 1,200 rounds through it so the parts should be new. I noticed a small dimple in the slide stop where the plunger touches it when it's *not* locking the slide back. That's the only dimple I've noticed.

[Sgt.K]

How would y'all diagnose this? to be clear, I *don't* see this as a benefit to me and I'd rather eliminate this from occurring. Any tips would be greatly appreciated!

I fully understand being unhappy when a firearm does not function as designed. That said:

If there was any change I would be interested in seeing on a 1911, it would be auto-dropping the slide on (full? loaded?) mag insertion. I see plenty of other competitors whose slides drop upon forceful insertion of a reload, and it would seem to be faster than having to use the slide release/slide stop or slingshotting the slide.

My 2¢
YMMV
etc...

[Hodgie]

I own a S&W M&P 9mm that does this exact same thing. I don't know why and have no solution for it.

S&W resolved this issue in the M&P 2.0, popular to the internet gun communities belief this was a defect and not a "feature" in the 1st generation.

[Parrisk]

Had a 1911 in the military that did that.. got chewed out on the range.. once I showed them the slide would release with no mag and a hard slap they made me turn it into the armorer.. On mine the slide stop where it engages the slide was severely worn or possible modified by a previous shooter. with the slide locked back and strike anywhere on the pistol would drop the slide.
He replaced the slide lock lever and fixed the issue

Of course we were shooting 1911s that rattled like a coffee can with a handful of change when you shook them

[cdi]

I hate to be really out of the loop but could you explain what the slide stop dimple should be like? This Springfield has just 1,200 rounds through it so the parts should be new. I noticed a small dimple in the slide stop where the plunger touches it when it's *not* locking the slide back. That's the only dimple I've noticed.

The "dimple" was a field expedient solution to holding the slide stop in position with a little more purchase. Like I pointed out, if your 1911 was correctly made there would be no need for the "dimple".
It's kind of like the "capture pins" sold for ar15's- they keep the trigger and hammer pins from walking out. If your pins, springs and lower are proper, the pins will not walk out.

What's happening in your pistol is as you forcefully insert a magazine, the pistol is jarred upward. The slide stop wants to remain still since it's not one piece with the gun. When the gun moves up, it leaves the slide stop standing still, which releases the slide.

It could also be magazine related. If the follower and magazine spring are not proper, the slide stop may not fully it's cut in the slide. Rack the pistol forcefully with an empty mag on board and see if the slide stop fully engages the notch in the slide when it locks open.